The SAID Principle and Transfer

After writing last week’s post on the meaning of strength, I was thinking about doing a post that would address whether getting “stronger” in the gym makes you stronger on the field. The big question is: to what degree will resistance training make you better at your sport? For example, will improving your deadlift make you better at soccer?

I have a previous post on the SAID principle which makes the point that exposure to any kind of stress, including resistance exercise, will cause adaptations that make it easier to withstand that specific form of stress. But because the adaptation is narrowly tailored to address a specific stress, it is unlikely that it will make you significantly better at a sport, which involves an entirely different set of specific skills.

This prompted some good questions from commenter Glenn, which resulted in a conversation that is not much different than the post I would have written on the issue of transfer. So here is the two-year old conversation, starting with Glenn’s initial response:

Glenn writes:

Very good post! But (and forgive me if this is answered elsewhere, I just found this blog) you seem come very close to suggesting that the only training necessary for soccer is playing soccer, the only training necessary for cycling is cycling, etc. But isn’t true that greater strength, in general, helps an athlete perform better and that improving strength requires loads that you just don’t get from playing the specific sport?

E.g. a stronger athlete can jump higher, but jumping alone does not necessarily make you stronger. (Actually, vertical jumping is a bad example, because it is an explosive movement that actually does recruit the fast-twitch fibers in a way that other sports movements don’t, but you get the point.) Squats done with a sufficient load will build stronger quads, hams, glutes, etc. which do translate to things beyond “being better at squatting.”

Would you suggest that someone who squats 315 and deadlifts 405 would be no better at moving a sofa compared to someone who squats 135 and deadlifts 185?

Anyway… maybe you address this somewhere else, but it seems this post is eliding, somewhat, the difference between skill adaptation and the overall strength adaptation that comes from a good program of compound-lift weight training.

That aside, this is a great blog!

Todd replies:

Thanks for the comments. I’m not saying strength gains will have no carryover on the field, just that it will probably have less than most people imagine. I would imagine that about 90% of getting good at soccer is achieved by playing soccer or doing soccer specific running or skill drills on the field. The weightroom will help prevent injuries and maybe improve some other factors a little, but most of it is just playing the game.

As far as moving sofas goes, I will take a guy who moves a lot of sofas over a guy who does a lot of deadlifts. Of course all things equal I’ll go with the guy who has a bigger deadlift.

Glenn replies:


With all due respect, I have to disagree. The idea that strength training has little benefit for athletes, who should mainly just practice their sport, is about three decades out of date.

You are vastly overstating the applicability of SAID (and defining it very narrowly). What SAID means is that if I do partial squats and don’t activate the posterior chain, I won’t get a stronger posterior chain. If my knees collapse because of weak abductors, I have to target my abductors, because they will only grow if I stimulate them. But… it does NOT mean that if I do proper squats and develop stronger legs, then I have only gotten stronger at performing squats. Strength is not that narrow.

I do heavy squats to develop a stronger vastus lateralis, biceps femoris, glute max and med, etc. When they get stronger, they are stronger. Period. I may need to develop the neural motor pathways to apply that strength to soccer kicks, e.g., but the strength itself does not flick off when I do leg work other than squats, and then mysteriously flick back on again when I put a barbell on my back.

You are also omitting a whole host of other responses that are elicited by heavy resistance training, including bone, tendon, and ligament strength; training the CNS to recruit fast-twitch fibers; the hormonal response, etc.

Despite this disagreement, I still love this blog!

Todd replies:


Thanks for the comments. ...

I don’t think I’m overstating anything here by saying most of getting good at sports is playing the sport. If you wanted to get much better at soccer and had 10,000 hours to practice, what percentage would you be on the field playing or practicing soccer versus time spent in the weightroom?

I would hope you would spend at least 90% of your time and energy on the field as opposed to working on your squat or deadlift. The weightroom would be supplementary and would mainly help to prevent injuries. Sure it might make you a little faster or quicker too, but most of soccer ability comes from playing soccer, not squatting.

If you get “stronger” glutes from squatting they are not stronger period. They are stronger at squatting and doing similar activities. Although the muscle fibers might be bigger period, they are hooked up to a nervous system that gets to decide when and how they fire. So yes, the strength does flick on and off when you change activities. “Stronger” legs won’t necessarily help you kick a ball harder or cut faster. In fact, lots of squatting could easily make you worse at ether activity if they cause a little pain, take time and energy away from skills practice, or change your movement patterns in some way.

Changes to bone tendon and ligament strength are certainly elicited by strength training and could be helpful for injury prevention on the field. Of course, they are also elicited by playing your actual sport, and in this case they are gained in exactly the places and amounts where they are needed, and not where they aren’t needed, as would be the case with adaptations gained in the weight room. Look at the pic of Nadal above. His left arm is way bigger than the right. That is from hitting a tennis ball, not lifting weights.

One final point. I don’t think that weight training is useless for athletes. I think it pales in comparison to actually playing your sport. Because you can’t play your sport all the time without getting hurt, it makes sense to get in the gym now and then. But this is supplementary, not primary.

Glenn replies:


Thanks for the reply… and your points are well taken. I think we may still disagree slightly on the percentages, but it’s just quibbling at this point. Looking forward to any new posts!

That’s it. Thanks to Glenn for the polite and productive conversation.

If you’d like to add to the debate, please leave a comment below.